Improvement in cupel-furnaces



S. G. WIGHT. ICupm-Furnace.

No. 220,895, l Patented, oct. 21,1879.

iLFErEHS, FHQTO-LITHOGRAPHER. WASHINGTON, o C.

UNITED STATES PATENT OFFICE.

STANLEY nGr. VVI-GHT, OF DETROIT, MICHIGAN.

, IMPROVEMENT IN cUPEL-FURNACES.

Specification forming part of Letters Patent No. 220,895, dated October 21, 1879,' application led June 16, 1879.

To all whom it may concern:

Be it known ,that I, `STANLEY G. WIGHT, of Detroit, in the county of Vayne and State of Michigan, have invented 'an Improvement in Gupel-Furnaces, of which the following is a specification.

`The nature of my invention relates to certain new and useful improvements in the construction of that class of furnaces usually elnployed in making assays of ores containing precious metals, whereby such a furnace, perfeet in its operation and results as any that are in use, can be so reduced insize as to. weigh but a very few pounds, adapted to be carried by the exploring assayist into his iield of operations, that the character and value of the ores can readily be determined at the point where discovered, and thereby avoiding the necessity heretofore existing of carrying the ores to some .point frequently at a long distance from their source; and the invention consists in the cupel-furnace heated by hydrocarbons, composed of the shell secured together in sections, a crucible supported in a luting of fire-clay and asbestus, a llue beneath the crucible, an opening connecting the rear ends of the flue and crucible, and a ledge at the mouth of the crucible, all mounted upon a suitable base, as fully hereinafter explained. s Figure l is a perspective View of my improved furnace, partially broken away to show the interior, and in section. Fig. 2 is a vertical longitudinal section.

In the drawings, which form a part of this specification and accompany it, A represents a shell, made of thin sheet-metal sections, each section being provided with ilanges a, by means of which and suitable bolts or rivets, b, the sections are secured together. y This shell forms the outer covering at the top and four sides, and isimperforated, except as shown at c, in the front, for the purpose of obtaining access to the interior, and at d, also in the front, for the admission ofthe necessary blast.

A smallcrucible, B, is inserted Within this shell, laid upon its side, so that the top or mouth of this crucible is presented at the opening c. The interior of the shell is then filled witha mixture of lire-clay and asbestus, which,

surrounding the crucible, holds the same in place. Thismixture is inserted from the top of the shell, which is left open for that purpose, and afterward the top section of the shell is secured in place, and a flue, e, is formed in this mixture or luting, coincident with and extending from the opening d (and immediately under the crucible) to a hole or aperture, h, in the side of the crucible, by means of which communication is had between the flue and `the interior of the crucible.

A flange -ledge, C, projecting from the front, as shown, is secured below the opening c, for the purpose of sustaining a removable stopper, D, which is preferably made of plumbago,) to be used whenever the fire is rfirst started, and again, for a moment or two, to intensify the heat, at the close of the operation.

This furnace is supported, but not secured thereto, upon a base, E, which is, preferably, an iron plate, prolonged to sustain a closed pan or reservoir, F, which has secured to its top a blow-pipe, Gr, one end of which is at-4 tached to any suitable implement to produce a blast, while the opposite end is inserted, when in use, into the opening d in the front of the furnace. A pipe, 7c, leading from the bottom and interior of this pan, enterso the blowpipe near its nozzle m.

In practice, the base button to be assayed is placed in proper cupels, H, the pan or reservoir filled with hydrocarbom'the stopper D placed to close, or nearly close, theuopening c after the cupels have been placed in the crucibles, and the blast applied, when the escaping hydrocarbon is ignited as the gas escapes from the end of the blowpipe. After the fire is well kindled, and the heat in the crucible has become intense, the stopper D is removed, to be replaced again only a moment or twol before the reduction process is complete.

The cost ofmy furnace is quite small, and its Weight not exceeding six or seven pounds, and its size renders it so easily portable that it may be added to the outfit of every expert explorer, to a great saving of time, labor, and expense in sending specimen ores a long dis tance to be assayed.

tus, a ue, e, connectinghole h, and ledge C, all mounted upon a, base, E, substantially as set forth.

STANLEY G. WIGHT. Witnesses:

II. S. SPRAGUE, A. BARTHEL. 

